I made sourdough for several months during spring to early summer and then - having previously been in a really good rhythm with my starter - I put the jar of starter in the fridge while we were away intermittently through the summer. Now I've taken it out of the fridge - about a week or so ago - and I feel completely all at sea with the thing 
here are my main issues:
I have fed it every other day or so but it continually smells incredibly vinegary no matter what I do;
It seems to look separated and topped with a greyish watery layer within a few hours of stirring or feeding it - I don't recall this happening before or at least not so regularly. Is this a concern? Am I doing something wrong? Should I be feeding it more?
And then yesterday I realised it was attracting fruit flies from a soggy kiwi in the fruit bowl. 
I have not discarded the starter even though it seemed to have some flies hanging around it. I've just changed from the manky old jar to a new improved one. But should I chuck it?!
Lastly, if I can crack to vinegary-ness, generally speaking how long after feeding it do you embark on starting to make a loaf? (I've forgotten this - duh!) and how long after it's been 'hibernating' should I wait before starting to use it again??
Thank you in advance - I'm so cross with myself for forgetting so much in such a short space of time! Must be getting old 